package net.wanho.controller;

import lombok.RequiredArgsConstructor;
import net.wanho.util.LockUtil;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.UUID;

/**
 * Author：汤小洋
 * Date：2023-10-08 10:52
 * Description：<描述>
 */
@RestController
@RequiredArgsConstructor
public class LockController {

    private final StringRedisTemplate redisTemplate;

    /**
     * 下单时判断库存：从redis中获取库存，检查库存是否够，库存数量>0才允许下单，此时库存数量-1
     */
    @RequestMapping("/deductStock")
    public String deductStock(){
        System.out.println(Thread.currentThread().getName() + "线程正在下单。。。。。。");

        /**
         * 每个人进来都要先获取锁，也称为加锁操作
         */
        String lockName="stock_lock"; // 锁的名称
        String value = UUID.randomUUID().toString().replace("-",""); // 锁的值
        if(! LockUtil.getLock(lockName,value)){
            return "获取锁失败！";
        }

        int total = Integer.parseInt(redisTemplate.opsForValue().get("stock"));
        if(total>0){
            try {
                Thread.sleep(5000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            total = total-1;
            redisTemplate.opsForValue().set("stock",String.valueOf(total));

            LockUtil.unlock(lockName, value); // 释放锁
            return "下单成功，库存还剩："+total;
        }

        LockUtil.unlock(lockName, value); // 释放锁
        return "下单失败，库存不足！";
    }

}
